Technical Field
Embodiments of the subject matter disclosed herein relate to engines. Other embodiments relate to engine diagnostics.
Discussion of Art
Engines may utilize recirculation of exhaust gas from an engine exhaust system to an engine intake system, a process referred to as exhaust gas recirculation (EGR), to reduce regulated emissions. Some EGR systems may include one or more valves to direct exhaust to an intake passage and/or an exhaust passage of the engine based on a desired amount of EGR. Under some conditions, the one or more valves may become stuck in undesired positions, or may be inadvertently mis-positioned. Further still, degradation of one or more of these valves may result in degradation in engine performance and/or eventual engine shutdown.